Many beverage and food container coatings employ bisphenolic-based polycarbonates or epoxies and related polyurethanes, where the bisphenolic compounds are bound as part of the polymer and/or are in a mobile form. A common synthetic method for polycarbonate basicifies a bisphenol compound such as bisphenol A (BPA) or bisphenol F (BPF) to form a bis(phenoxy) salt, and condenses that product with phosgene (COCl2) to form the polycarbonate. Protective coatings are applied to the interior of metal and other food and beverage containers (e.g. cans) to prevent the contents from coming into contact with the metal surfaces of the containers to prevent corrosion of the metal and contamination and deterioration of the contents.
Polycarbonates and the related bisphenolic-based epoxies and polyurethanes are colorless, tasteless, and odorless. The balance of currently available scientific evidence indicates that trace amounts of bisphenolics that might diffuse away from existing coatings, whether origination from contain mobile or bound bisphenol compounds, do not pose a significant health risk to humans. However there is a perception that some coatings such as epoxy-based coatings and the like containing mobile BPA, bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE) are less desirable for foodstuffs storage and might soon fail to meet established government regulatory standards. Concerted efforts have been made to find replacements that are free of the bisphenol compounds. Currently, most of the promising replacement coatings are based on a combination of polyester and a polyacrylate, however, BPA- and BPF-free epoxies are not a ready option.
It would be advantageous to provide a protective coating for a packaging container (e.g., a food or beverage can) that is coated with a composition that is substantially free of mobile BPA and related compounds. These needs and other needs are addressed by the compositions, methods, and products of the present disclosure.